Origins

• Before Christianity spread widely across Europe, many native peoples had various earth-inspired deities to honor and worship. Cultures in northern Europe in particular revered trees as gods, as a symbolism of life or the honorable source of wood for the built structure. Once a wooden building was completed, a tree or bough was mounted to the top of the roof to honor the gods. Over generations, the meaning of a tree atop a roof changed to bring a blessing of prosperity or fertility to those who resided in the building.
  
  

Modern Context

• When construction craftsmen emigrated from Europe to North America, the tradition of placing a tree or bough atop a completed structure came with them. Initially, only when the building was fully complete would the tree be mounted on the highest point of the roof in public exposition. Today, topping out ceremonies -- formal or not -- occur when the highest part of a structure is completed. The roof may be complete but the inner floors or side walls not yet enclosed. The tree may still be wedged or tied on the rooftop to signify completion of the structure's pinnacle.
  
  

Other Applications

• Steelworkers during the American industrial revolution also adopted the use of topping out when putting together skyscraper skeletons. While the towering building or structure, such as a bridge, is not enclosed and complete, a tree or bough is placed once the highest steel beam or flagpole is mounted. Again, topping out signifies completion of the construction at the highest, most prominent point of the structure.
  
  

The Chimney

• Topping out may take place on construction of new buildings or the replacement of a roof or chimney. It depends on the construction workers and their traditions. On houses, rooftops often have a steep incline with a narrow top and sharp gable. Walking atop the roof isn't easy since it's quite narrow and sharply pitched. Rather than place a potted or burlap-balled tree on an uneven surface, the chimney provided a flat location to mount and display the tree. The chimney also rises higher than the roof gable, making it a more appropriate, highest-elevation location for the tree.